/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package javax.faces.event;

import javax.el.ELContext;
import javax.el.ELException;
import javax.el.MethodExpression;
import javax.faces.component.StateHolder;
import javax.faces.context.FacesContext;

/**
 * See Javadoc of <a href="http://java.sun.com/javaee/javaserverfaces/1.2/docs/api/index.html">JSF Specification</a>
 *
 * @author Stan Silvert
 */
public class MethodExpressionActionListener implements ActionListener, StateHolder {
    
    private MethodExpression methodExpression;
    
    private boolean isTransient = false;
    
    /** Creates a new instance of MethodExpressionActionListener */
    public MethodExpressionActionListener() {
    }
    
    public MethodExpressionActionListener(MethodExpression methodExpression) {
        this.methodExpression = methodExpression;
    }

    public void processAction(ActionEvent actionEvent) throws AbortProcessingException {
        try
        {
            Object[] params = new Object[]{actionEvent};
            methodExpression.invoke(elContext(), params);
        }
        catch (ELException e)
        {
            Throwable cause = e.getCause();
            if (cause != null && cause instanceof AbortProcessingException)
            {
                throw (AbortProcessingException)cause;
            }
            else
            {
                throw e;
            }
        }
    }
    
    private ELContext elContext() {
        return FacesContext.getCurrentInstance().getELContext();
    }
    
    public void restoreState(FacesContext context, Object state) {
        methodExpression = (MethodExpression)state;
    }

    public Object saveState(FacesContext context) {
        return methodExpression;
    }

    public void setTransient(boolean newTransientValue) {
        isTransient = newTransientValue;
    }

    public boolean isTransient() {
        return isTransient;
    }
    
}
